platform_bionic/libc/arch-x86/bionic/__bionic_clone.S
Elliott Hughes 0d236aa3f1 Align the child stack in clone(2).
Also let clone(2) set the TLS for x86.

Also ensure we initialize the TLS before we clone(2) for all architectures.

Change-Id: Ie5fa4466e1c9ee116a281dfedef574c5ba60c0b5
2014-05-09 17:06:51 -07:00

52 lines
1.4 KiB
ArmAsm

#include <private/bionic_asm.h>
// pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
ENTRY(__bionic_clone)
pushl %ebx
pushl %esi
pushl %edi
# Load system call arguments into registers.
movl 16(%esp), %ebx # flags
movl 20(%esp), %ecx # child_stack
movl 24(%esp), %edx # parent_tid
movl 28(%esp), %esi # tls
movl 32(%esp), %edi # child_tid
# Copy 'fn' and 'arg' onto the child stack
movl 36(%esp), %eax # Read 'fn'.
movl %eax, -16(%ecx) # Write 'fn'.
movl 40(%esp), %eax # Read 'arg'.
movl %eax, -12(%ecx) # Write 'arg'.
subl $16, %ecx
# Make the system call.
movl $__NR_clone, %eax
int $0x80
# Check result.
cmpl $0, %eax
je .L_bc_child
jg .L_bc_parent
# An error occurred, so set errno and return -1.
negl %eax
pushl %eax
call __set_errno
addl $4, %esp
orl $-1, %eax
jmp .L_bc_return
.L_bc_child:
call __bionic_clone_entry
hlt
.L_bc_parent:
# we're the parent; nothing to do.
.L_bc_return:
popl %edi
popl %esi
popl %ebx
ret
END(__bionic_clone)
.hidden __bionic_clone